Commits on Jan 4, 2017

1. std: Don't pass overlapped handles to processes …

   This commit fixes a mistake introduced in rust-lang#31618 where overlapped handles were
   leaked to child processes on Windows. On Windows once a handle is in overlapped
   mode it should always have I/O executed with an instance of `OVERLAPPED`. Most
   child processes, however, are not prepared to have their stdio handles in
   overlapped mode as they don't use `OVERLAPPED` on reads/writes to the handle.
   
   Now we haven't had any odd behavior in Rust up to this point, and the original
   bug was introduced almost a year ago. I believe this is because it turns out
   that if you *don't* pass an `OVERLAPPED` then the system will [supply one for
   you][link]. In this case everything will go awry if you concurrently operate on
   the handle. In Rust, however, the stdio handles are always locked, and there's
   no way to not use them unlocked in libstd. Due to that change we've always had
   synchronized access to these handles, which means that Rust programs typically
   "just work".
   
   Conversely, though, this commit fixes the test case included, which exhibits
   behavior that other programs Rust spawns may attempt to execute. Namely, the
   stdio handles may be concurrently used and having them in overlapped mode wreaks
   havoc.
   
   [link]: https://blogs.msdn.microsoft.com/oldnewthing/20121012-00/?p=6343
   
   Closes rust-lang#38811

   

   alexcrichton committed Jan 4, 2017
   Configuration menu

   • View commit details
   • Copy full SHA for 5148918
   • Browse repository at this point

   Copy the full SHA

   5148918 View commit details

   Browse the repository at this point in the history